LOS ANGELES (July 17, 2012) - The stacked September 15 "Knockout Kings" quadruple-header at the MGM Grand Garden Arena in Las Vegas, Nev. just got another shot of pugilistic adrenaline, with the addition of former Super Lightweight World Champion Marcos "El Chino" Maidana. The champion continues his quest for a second world title at 147 pounds in what promises to be an action-packed showdown against Mexico's Jesus Soto Karass.

This 12-round special attraction is the third fight announced for what is shaping up to be the most exciting boxing event of 2012, with the fourth fight scheduled to be announced in the near future.

"Knockout Kings," headlined by Canelo Alvarez defending his WBC Super Welterweight World Championship against Josesito Lopez, is presented by Golden Boy Promotions and Canelo Promotions in association with Goossen Tutor Promotions and Thompson Boxing Promotions and sponsored by Corona, DeWalt Tools and AT&T. In the co-featured attractions, WBC Featherweight World Champion Jhonny Gonzalez defends his crown against former World Champion Daniel Ponce De Leon in fight presented in association with Promociones Del Pueblo and former World Champion Marcos Maidana faces perennial contender Jesus Soto Karass in a fight presented in association with Universum Box-Promotion. The Saturday, Sept. 15 quadruple-header, packed with Mexican pride and power, will take place at the MGM Grand Garden Arena in Las Vegas, Nev. and will be televised live on SHOWTIME.

SHOWTIME Sports will produce a new edition of its ALL ACESS sports documentary series. ALL ACCESS: Canelo vs. Lopez will premiere on SHOWTIME with multiple replays on additional SHOWTIME and CBS platforms. The exhibition schedule also will be announced shortly.

"This fight is a great match-up which has 'Fight of the Year' written all over it," said Oscar de la Hoya, president of Golden Boy Promotions."Both of these fighters hit with power, have great chins and fight one way...coming forward. Mix in the fact that it's a must win fight for each of them and you have the recipe for a classic."

"I always appreciate the opportunity to fight on the big time boxing event like this one," said Maidana. "Throughout my career I have always heard I fight like the great Mexican fighters and that Mexican fans love to watch me fight. I will give them something to cheer about on September 15 when I win the fight and move one step closer to getting another world title."

"I am very fortunate to be fighting on this card alongside my fellow countrymen Canelo, Daniel and Jhonny," said Soto Karass. "We are going to represent Mexico well that night and I plan to be victorious against Maidana. I have worked hard my whole career to have my dream of being a world champion come true and I feel that with each fight, I get closer to it."

Buenos Aires, Argentina's Marcos "El Chino" Maidana (31-3, 28 KOs) has been a worthy member of his country's fighting fraternity, but one look at his style in the ring will make it evident that he is not satisfied with one world championship. Maidana held the WBA Interim Super Lightweight and WBA Super Lightweight World Championships from 2009 to 2010, a span during which he stopped "Vicious" Victor Ortiz and defended the belt three times before losing it to Amir "King" Khan in 2010's Fight of the Year. Maidana reclaimed the belt in 2011 with another classic against Erik "El Terrible" Morales, but after one defense, he moved up in weight to 147 pounds. After a loss to Devon Alexander "The Great" in February, the 29-year-old will seek his first welterweight victory on September 15.

Coming off one of his career-best performances on July 7, a blistering fifth round stoppage of Euri Gonzalez, 29-year-old Jesus Soto Karass (26-7-3, 17 KOs) looks like he has started the march to his well-deserved first world title shot. An 11-year professional who has collected an overflowing pile of regional titles, the native of Los Mochis, Sinaloa, Mexico has bounced back from a recent cold spell to defeat hot prospect Said El Harrak and Gonzalez in consecutive 2012 fights. The next mountain to climb is taking on former World Champion Maidana and Soto Karass has every intention of keeping "El Chino" winless at 147 pounds.

Tickets priced at $400, $300, $200, $100, $50 and $25, not including applicable service charges and taxes, go on sale Friday, July 20 at Noon PT. Ticket sales are limited to ten (10) per person. To charge by phone with a major credit card, call Ticketmaster at (800) 745-3000. Tickets also are available for purchase at www.mgmgrand.com or www.ticketmaster.com.